I’m : a programmer, writer, podcaster, geek, and coffee enthusiast.

Cold-brewed coffee results

My first batch of cold-brewed coffee didn’t turn out very well.

One problem was filtering it. I don’t yet own a good coffee grinder (the best are the conical burr grinders). In fact, I don’t own a coffee grinder at all: since my pre-Brooklyn life involved very little coffee-making at home, I’ve just been using a Magic Bullet. (Really.) And it’s just as good as any other typical spinning-blade grinder.

The problem with spinning-blade grinders is that they don’t make a consistent grind. No matter how long you hold the button down, you’ll have some bigger chunks, some fine powder, and the full range of intermediate sizes, all mixed together. (If you’ve ever used a food processor, it’s the same effect: some stuff gets thrown to the sides too quickly and doesn’t get chopped enough, and the stuff in the middle gets puréed.)

The cold brew requires a very coarse grind because you need to use a lot of grounds to get enough flavor to matter. If you have too many small, powdery particles, they’ll either pass through your filter or, more likely at this volume, clog it.

And that’s what happened to mine: as I was pouring the mixture through my drip pot’s metal cone filter, it clogged the hell out of it and made it extremely difficult to strain the liquid out. (What did come out contained a lot of sludge from the tiniest particles that made it through.)

The most practical filtering method for cold-brew, I think, is a large French press, like this popular one that I have. But a French press is very sensitive to grind consistency. The filter mesh’s holes are large (by necessity), and it needs a true coarse grind with no fine particles to avoid making sludge in your cup. So you really need a high-quality coffee grinder.

(Alternately, you could just get your coffee ground at a French-press setting from whoever you’re buying the beans from, since they’re likely to use a nice big commercial flat-burr grinder. But then you’d be buying ground coffee, and I’m just not ready to compromise my morals like that.)

I took this as an excuse to finally order myself a real coffee grinder. I really had no excuse before, and my home coffee has never been quite as good as I want it, and I always have sludge at the bottom of the cup, and I’ll finally be able to use the French press effectively. Since I tend not to buy coffee grinders very often (I’ve purchased zero of them in 27 years), I went all out. I’ll have it in a few days.

But I did have some cold-brewed coffee that was full of sludge and took forever to strain. So I figured I might as well taste it.

Sip… hmm… there’s some coffee flavor there… but where’s the rest of it? It’s not like weak coffee: it’s like a strong-enough version of only the bottom half of the flavor profile.

Had I read the article that inspired this experiment more carefully, this wouldn’t have been a surprise:

Jim Reynolds, brewer emeritus and longtime taster for Peet’s Coffee & Tea, says he’s always considered the flavor of cold-brewed coffee to border on insipid and bland […]


Remember that first time you drank coffee, as a kid, and the taste didn’t quite live up to that amazing smell? Cold-brewing does a lot to close the smell-taste gap. Taste is in the chemistry, and exposing coffee grounds to hot water releases oils that won’t dissolve at lower temperatures. These oils are full of acidic compounds that give coffee its famous bitter bite. […]

I don’t disagree with this, but I interpret the mechanics a bit differently:

The paragraph ends with this:

Is it any wonder that so many people add so much milk and sugar?

And here’s where our opinions diverge.

Most people add milk and sugar because they’ve only ever had bad coffee as a result of extremely stale beans, not enough grounds to water, and awful coffee makers. Bad coffee needs milk and sugar to be palatable to nearly anyone. And most people have no idea what they’re missing. Listening to someone rave about the great coffee from their office’s new pod-canister machine or the great new brew at Starbucks is like hearing a repressed, middle-aged woman say “I’ve had orgasms before… I think.”

To them, cold-brewed coffee is probably an acceptable substitute.

But if you like what coffee really is, you need the full flavor, and cold-brewing just can’t get it.